Crowns & Bridges
A crown or cap would be recommended if a tooth is badly broken down by decay and a conventional restoration would not be suitable. Also if a tooth has a root canal then your dentist would advise you to get a crown in order to avoid fracture of the brittle tooth underneath. The crown covers the tooth entirely to restore it to a natural form and appearance and protects it from biting pressure. (like a cast for a tooth). A crown can change the shape and colour of a tooth if badly damaged.
A bridge is a fixed solution to replace one or more missing teeth. Teeth on either side of the space are connected by crowns to support the missing teeth.